Pen



FIG. 1 is a rear elevational view of our new design;

FIG. 2 is a front elevational view;

FIG. 3 is a top perspective view;

FIG. 4 is a left side elevational view;

FIG. 5 is a bottom plan view;

FIG. 6 is a right side elevational view; and,

FIG. 7 is a top plan view.

The pointing device and tablet shown in broken lines in FIG. 3 are environmental matter and form no part of the claimed design. 

The ornamental design for a pen, as shown and described. 